Chocolate Affair
by NMTD
Summary: Nami and Sanji are acting strange lately, so Usopp does some snooping around. Valentine's Day one shot. Canon fic. UsoNa


**A/N:**

 **Happy Belated Valentine's Day! I'm sorry this is a few days late. The plot bunny came to me just after Valentine's Day demanding to be written.**

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Usopp sees the first hint of it at Robin's birthday party. The cake Sanji has made for the feast is a chocolate mocha mousse cake, one of Robin's favourites of course, and as always, it tastes heavenly. That's not what catches the attention of the long nose though. It's something a little strange, something that's not what he knows as routine with this crew, something that bugs him to no end for the following days. It's Nami's reaction to her first bite of the cake. Instead of brushing the pestering cook aside with her usual quick thanks and casual half-hearted compliments, she pauses as she rolls around the small spoonful of cake in her mouth as if carefully pondering the flavour. If that's not enough to set off alarms, next she turns to whisper in the cook's ear. Then the handsome blond player-of-a-cook, instead of putting on the lecherous grin and doing that cringe-worthy mating dance he always does, leans down to reply with another whisper before giving the navigator a knowing look.

Then he sees it. Nami blushes. Nami never blushes unless she's using it to wrap a man around her little finger so she can get the location of the treasure chest out of him. This is not it though. Sanji has been wrapped around her little finger since day one, and Sanji doesn't have a treasure chest. Even if he had one to begin with, it probably already belongs to Nami. What's more, the blond then shoots a warning glare in Usopp's direction, as if to say, "Back off! She's mine!" Usopp cowers instinctively.

The next thing he notices is how the blond stops his over-the-top declarations of love. Instead, there seems to be more and more times when Usopp catches Sanji giving the red head special treats on tiny dessert plates that he doesn't offer to anyone else, even Robin. Whenever that happens, Nami would give him that serious face of consideration again before sharing another short intimate conversation that's kept out of earshot of anyone else on crew. There's even once or twice when Usopp sees Nami letting Sanji pick perfectly ripe tangerines from her precious groves and pealing them to share between the two. All the older members of the crew know just much that simple gesture means for the navigator.

Then one night a couple days later when Usopp is on the first night watch, he catches sight of the two of them meeting in the galley alone after everyone else has gone to sleep. They spend two hours and seventeen minutes in there as Usopp glues his eyes to every flickering of light through the galley windows before watching Nami make her way back to the girls' dorm to grab a change of clothes and head to the bathroom in the dark. Then Sanji follows the suite after Nami returns to her room, grabs his clothes from the boys' dorm, and makes his way to the back of the ship.

The pattern repeats nightly with Sanji sneaking out of the boys' dorm after everyone falls asleep (or in Usopp's case, pretends to fall asleep), coming back a couple hours later smelling of fresh floral shampoo and humming softly under his breath. On Day Six of the secret nighttime meetings, Usopp finally decides to find out once and for all what they've been doing. He waits until Sanji sneaks out of the room and patiently counts another 15 minutes before making his way to the galley as quietly as possible. He presses his ear to the door for a minute or two, and when he can't make out much of what their muffled voices are saying, he takes a chance and peaks into a window.

There they are with their backs to Usopp, Nami awkwardly holding a pot over the stove, and Sanji gently guiding her hands with his while cooing instructions into her ears. They are in the middle of a cooking lesson. That fact alone is a testament to the intimate nature of the bond that's forming between them. Nami never willingly lets herself be ordered around, and Sanji never shares his sacred cooking space and precious cooking equipments with an amateur cook. Yet here they are.

Usopp silently watches the scene through the window half in thought until he's jolted back to reality by an icy glare from the blond. Damn, he's forgotten about Sanji's Observation Haki. The cook flashes him a smirk before dipping a finger into the pot and muttering something in the navigator's ear. Nami, who still seems oblivious to Usopp's presence, leans forward and sucks the sauce off Sanji's outstretched finger, rolling it around in her mouth and analyzing the flavour. The blond raises a triumphant eyebrow at the instantly heart-broken liar beyond the window.

Well of course Nami would fall for the cook, Usopp concludes as he polishes the newest version of Nami's Clima-Tact. Despite the fact that Sanji acts like an idiot around women, he pampers and worships them, and Nami likes being pampered and worshipped. Not to mention the blond's quite handsome and classy if he can keep that goofy expression off his face. Plus they have a common interest in fashion, and now in cooking as well. On top of all that, the cook's strong in battle, which is always a bonus in a boyfriend for someone with as strong a sense of self-preservation as Nami. Besides, Sanji's been after her since the day they met. It makes sense why they'd end up together.

But Usopp still worries about that idiot's ability to understand her. Nami likes to think she's manipulating everyone instead of people willingly giving in to her requests out of consideration. It makes her feel at ease. Usopp hopes Sanji knows that. Nami wants to stand her own ground during battles with her science and wits instead of being shielded from danger all the time by the monster trio. It assures her of her self-worth on the team. Usopp hopes Sanji knows that. Nami puts up a tough and confident front, but she can be really insecure and self-conscious at times about her bad temper and violent outbursts. Usopp hopes Sanji knows that. Nami boasts about her looks all the time, but she really prefers compliments to her intelligence instead. Usopp hopes Sanji knows that. He runs a hand along the now smooth surface of the Clima-Tact. He's sure nobody on this ship understands Nami better than him, but if Nami's happy with the cook, who is he to question her choice?

Usopp makes his way up to the galley, where he's sure Nami is hiding out and sharing another one of those secret snacks with the blond. He's slightly surprised when he finds Sanji alone making preparations for dinner. The cook doesn't even bother to look up from his chopping board as he speaks with a hint of irritation.

"What do you want, shitty nose?"

Everyone in the crew knows not to bother the cook when he's cooking under time pressure, and apparently that's exactly what he's doing at the moment. It takes all of Usopp's will power to stop his survival instinct from taking over and ducking him out of the room after a quick mutter of "nothing". Instead, he tries to stand tall with his slightly shaking legs as he fixes a glare (or as close to a glare as he can manage) at the cook's back.

"What? Make it quick. I'm busy." Sanji finally pauses and turns to him after a long moment of silence. Usopp swallows thickly and tries to steady his wildly beating heart.

"L-listen Sanji, i-i-i-if you e-ever make N-Nami cry, m-m-m-me and my eight thousand underlings w-w-won't let you off s-so easy!" He points a shaky finger at the blond but quickly retracts it to protect his head when he sees a vein pop in anger on the blond's forehead. The next thing he knows, he's kicked in the chest before flying through the door and landing hard onto the grassy deck.

"I don't want to hear that from you, fucking shithead!" Usopp hears the cook yell and slam the galley door before he can stand up again.

Usopp doesn't know why the screwed up situation still sparks such strong curiosity in him, but he can't seem to rest easy until he finds out the precise dish Sanji is teaching Nami at night. Nami is a weight watcher and doesn't eat snacks after dinner, and Sanji hates throwing food out, which means whatever they make during their cooking lessons would still be in the fridge at least until the next morning. He's not one of the chosen ones Sanji shares his fridge lock password with (He's sure that category includes only the girls), but no password is too difficult to unlock for the great Usopp-sama, especially when Chopper's stethoscope is sitting on his desk just next door. It's not like he fixed Nami's Clima-Tact for free all this time. He's received a few pointers from the legendary Cat Burglar herself.

He lies wide awake in his hammock bed until he hears Sanji fall asleep after his secret meeting for the night before he sets Operation Curious George in motion. It takes him a good half an hour before he figures out the password. He's not nearly as practiced at it as Nami after all. What greets him when he finally pulls open the heavy fridge door is a plate of handmade chocolate pieces being chilled overnight. He counts ten half-moon shaped wedges, seven in various shades of brown, three in white, each covered in a unique design of embellishments of icing. Come to think of it, that makes sense. It's almost Valentine's Day, and Nami's not the type to let such an investment opportunity go to waste. Of course she'd prepare chocolate for the whole crew so she can collect, no, demand better return gifts in a month's time*.

But no matter how he counts, the numbers don't match. There are nine members in the crew. Even if you exclude Sanji and Nami themselves, there are only seven, not ten. Not to mention Sanji is not one to neglect holiday gifts especially when it's food-related, but there's only one set of chocolates in the fridge. Could this be a gift to the crew from the two of them together as an announcement that they're now officially... dating? Usopp's heart sinks as he notices that the pink icing on the three white pieces can be put together to form the shape of a heart. Oh, so those are their gift to each other. They made three pieces for the two of them because they share the number three.** Now the numbers all match. Deciding he's seen enough, he closes the fridge and drags himself back to bed.

The next day after dinner, Sanji insists on having Usopp help him with the dishes, sending death threats through glares to silence the long nose when Usopp tries to protest. The cook seems to be in such a foul mood that Usopp doesn't dare making a peep while the dishes are being washed, dried, and put away. If the cook is this angry at him for sticking his nose (no pun intended) in their new relationship, he should just kick the liar out of the kitchen like last time. It's been a depressing enough week for him without the explosive cook at his back.

To his surprise, the cook loads his serving platter with a bottle of expensive looking rose sparkling wine, two champagne flutes, a small vase holding a single stem of rose, and a small lighted candle.

"Take this up to the crow's nest. If you knock anything over in the process, I'll give you a much shorter nose this time." The cook growls dangerously as he slides the platter across the kitchen island. Instinct tells Usopp that he should just follow the order without a question for the safety of his poor nose, but red flags raise themselves in all corners of his mind as he remembers Robin mentioning that it's Zoro's watch tonight. It's not that Usopp has anything against Sanji's rumored change in "preferences" since their two years apart, but if he has a romantic evening planned with the swordsman and using Usopp as their delivery boy, where does that leave Nami?

"Does Nami know about this?" Usopp asks quietly, gesturing to the platter.

"Stop asking stupid questions and just go." Sanji turns his back to him and proceeds to wipe the counters with a towel. He's avoiding the question. A surge of rage overtakes any remaining instinctual fear as Usopp repeats his question.

"I'm asking if Nami knows about your romantic evening with Zoro!" Powered by anger, his voice comes out much stronger this time.

"What the fuck are you even talking about?" Sanji flicks the towel into the sink as he turns to face the long nose again. Usopp steps forward to yank the loose tie around his neck.

"Which part of this are you pretending not to know about? The part where you're having an underground relationship with Nami for the past week, or the part that you're cheating on her with Zoro tonight?" Usopp throws a punch, knocking over the platter. The flame from the candle flickers and dies before everything else is shattered on the kitchen floor. The galley door swings open a moment later.

"Hn~? Since when are you capable of cheating on the sea witch, shit cook?" Usopp freezes in utter confusion as he watches Zoro casually make his way to his usual seat and put his feet up on the table. Sanji takes the chance to kick the long nose across the room and to fix his tie before speaking again.

"Tread lightly, shitty moss. I'm in a bad mood today." The cook lights himself a cigarette before crouching down to examine the mess on the floor. "There goes the best wine I can find." He exhales slowly before sending another bone-chilling glare at Usopp, who's struggling to untangle himself from the leg of a chair.

"Here Marimo, make yourself useful and take that hostile and ungrateful puppy over there up to the crow's nest before I change my mind and mop the floor with his nose." The blond spits through gritted teeth, and the swordsman snorts in amusement.

"And what do I get in return, princess?"

"That'd depend on how quickly you get it done and how much you irritate me with the name calling in the process."

Upon hearing that, the swordsman bends to pick up Usopp by the back of his collar and throws liar over his muscular shoulder like a sack of potatoes. After a few long minutes of all his protests being completely ignored, Usopp finds himself being thrown through the trap door onto the wooden floor of the crow's nest, landing on his face and skidding a couple feet toward one of the benches.

"Oh hey, you made it!" Nami's voice hums from the bench directly before him. That's weird. Sanji sent him here to see Nami? What is this? Oh, right, it must be his turn to receive the chocolates they made.

"So you switched your shift with Zoro for the watch? Robin said it was his watch." Usopp asks as he scrambles to put himself in a more dignifying, sitting posture on the floor. He can do a bit of small talk to distract himself from the inevitable announcement coming in a minute.

"Hm? Oh yeah, I did." Nami absentmindedly answers as she pulls out a wrapped box from her... bra. It's bigger than expected, but then again, if Sanji's the one who packed it, Usopp wouldn't be surprised if it includes a lot of empty space just for visual effects. Nami shoves the box at him without a word. Usopp takes it as a sign that the exchange is over. He raises the box, mutters a quick "thanks", and heads for the trap door, being thankful that he doesn't have to hear the announcement directly from the girl he likes. Maybe he'll find a note in the box or something, but at least he can throw it away when he sees it.

"Wait, where are you going? Do you even know what that is, idiot?" Nami nervously follows him to the trap door.

"I can guess. Valentine's Day chocolate, right? And I know, you'll be expecting a return gift. Don't worry. I won't cheat." Even if this is a heart-breaker chocolate, he'd still prepare a return gift for the two of them as his blessing. It'll make Nami happy.

"At least open it, dumbass!" Now she sounds mad. Well OK, he has to see it sooner or later anyway. He wrestles with the ribbon and the wrapping paper for a minute or two and opens the box. Inside he finds not one but all ten pieces of chocolate that he saw the night before, arranged in a circle. He frowns.

"This is all for me? What about everyone else's share?" His confusion only seems to anger Nami further.

"And _why_ would there be anyone else's share?" She asks and runs a hand over her Clima-Tact, daring him to answer that question. Usopp wisely decides to shut up and examine the box of chocolate instead. There's a small card that's sitting snugly on the bottom of the box, right under the chocolate pieces.

"Eat them first." Nami orders, and Usopp complies out of fear. He's surprised yet again as he takes his first bite and finds that it's actually a piece of tangerine completely covered in chocolate, giving its taste the perfect balance of sweet and refreshing. He looks back to the remaining pieces and notices for the first time how well they fit into a circle. These are made from a single tangerine, broken into pieces and each coated in chocolate. Nami made this? For him? He looks up to find Nami staring at him expectantly, her large brown eyes shining with a little anxiety and a lot of excitement. Usopp eagerly finishes the box.

"Now read the card." Nami gives him an urging smile, seemingly satisfied with his reaction to the chocolate. Usopp reaches to the bottom of the box and opens the card.

 _Dear Usopp,_

 _Now that you've accepted all of me, I expect to receive all of you on White Day*, plus interest._

 _Happy Valentine's Day!_

 _Love,_

 _Nami_

"All of me..." Usopp reads under his breath. That's why there were seven brown pieces and three white pieces.** Well, there he is walking straight into another one of Nami's carefully laid debt traps. But...

"What about Sanji? Weren't you..." Understanding dawns on him before he finishes his sentence. Nami has asked Sanji for help to prepare this gift. That's why Sanji hated his guts.

"Hmm? What, were you jealous?" Nami teases.

"N-not at all! Of course the great warrior Usopp-sama knew all along that _he_ is your one and only knight in shining armour!" Usopp sticks out his chest and stands as tall as he can.

"I see." Nami whispers as she presses a light kiss to his jaw, no doubt filing yet another one of his weakness for future blackmailing.

Usopp doesn't mind though. Being indebted to Nami isn't all that bad.

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 **A/N:**

 ***In Japanese culture, women give chocolates to the men in their lives in Valentine's Day (Feb. 14th), and the men who receive chocolates are expected to give a return gift on White Day (Mar. 14th), but you already know that because you watch anime. :P**

 **** In Japanese language, nana = 7, mi = san = 3, ji = 2nd, so Nami = 7 3, Sanji = 3 2.**

 **And in case you ask, yes, Zoro and Sanji are in an established relationship here.**


End file.
